Scientists working with the National Aeronautics and Space Administration, or NASA, are preparing to launch a rocket from Florida's Cape Canaveral Monday on a mission to the planet Mercury. The Messenger spacecraft will not go into orbit around the closest planet to the sun for several years, but when it does it will have the instruments needed to unlock many secrets.

Mercury is a mysterious planet. Scientists are intrigued by a number of phenomena on this little-explored planet and believe that a better understanding of it would yield important information about earth as well. The one and only time a spacecraft did fly by Mercury resulted in photographs of one side of the planet that led to more questions than answers.

This current mission is directed at answering a whole array of intriguing questions, according to Messenger Science Payload Manager Robert Gold.

"Thirty years ago there was a fly-by by the Mariner 10 spacecraft that actually took some crude pictures of less than half the planet," he explains. "So, we want to know what does Mercury look like? Once we know what it looks like, we want to know how did it get that way and what kind of geology led to this? What is it made of?"

After spending eight years developing the scientific payload for this mission, Robert Gold and other NASA scientists are now facing another long wait. Even if the launch goes off without a hitch on Monday, the Messenger spacecraft will not reach Mercury until January 2008 for the first of three fly-by looks at the planet. In March 2011, Messenger will ease into an orbit around the planet. At that time two cameras will make detailed photos of Mercury's surface and landforms. These will be used to make a detailed map of the planet. Other instruments will collect information about the planet's magnetic field, its mass and its composition.

Even though that is all still several years away, Robert Gold says he cannot wait for Monday's launch.

"After dedicating many years of my life to this, not only am I excited, this is going to be one of the greatest things that ever happened and I am sort of standing on pins and needles until it actually gets off," he says.

One of the most intriguing questions about Mercury are formations that some scientists believe could be ice. This may seem odd since Mercury is eleven times brighter than earth and has surface temperatures as high as 448 degrees Celsius. But Robert Gold says the axis of the planet leaves some areas in continual shade and temperatures there would remain very cold.

If all goes well, the beginning of the mission to answer these questions will start with the launch of the rocket carrying Messenger into space on Monday.